JPH09216065A - Industrial robot torch rotation device - Google Patents

Abstract

(57) Abstract: A robot wrist portion 15 rotatably supported by a tip portion of a robot arm 1 about an axis b substantially perpendicular to the longitudinal direction, and a robot wrist portion 15 supported by the robot wrist portion 15. The rotation range of the torch 30 extending in a direction substantially perpendicular to the rotation axis b is not restricted by the cable 35 or the like, and the degree of freedom of the posture of the torch 30 and the position of the nozzle 33 at the tip thereof is increased. The teaching work of the robot is simplified. SOLUTION: The robot wrist 1 is provided with a robot arm 1
The robot 20 is disposed laterally of the robot to support the torch 30 on the robot wrist 15 so as to be rotatable about its central axis, and to rotate the torch 30 about its central axis.
To be installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an articulated industrial robot having, for example, five-axis or six-axis degrees of freedom,
It belongs to the technical field relating to a torch rotating device for rotating a torch for performing welding, cutting and the like.

[0002]

2. Description of the Related Art Conventionally, as a torch rotating device for this type of industrial robot, a robot torch rotating device having five axes of freedom is known, as disclosed in, for example, Japanese Patent Publication No. 5-49437. Has been. That is, in this structure, the rotating body is rotatably supported on the fixed member so as to be rotatable about the vertical rotation axis, and the base end portion of the first arm is rotatable on the upper side of the rotating body about the horizontal axis. Is pivotally supported, and the base end portion of the second arm is rotatably supported by the tip end portion of the first arm so as to be rotatable around the horizontal axis, and a concave portion is formed in the substantially central portion of the tip end portion of the second arm. A robot wrist is formed in the recess and is rotatably supported about an axis substantially perpendicular to the longitudinal direction of the second arm. A torch rotation unit is rotatably supported on the robot wrist so as to be rotatable about an axis substantially perpendicular to the axis of rotation of the robot wrist. A torch mounting arm extending in a direction substantially perpendicular to the axis of rotation of the torch is integrally projected to the torch rotating portion, and a torch mounting tool provided at the tip of the torch mounting arm is provided with a rotation axis of the torch rotating portion. A torch support portion extending substantially in parallel is formed, and a welding torch is attached and fixed to the torch support portion.

The rotating body, the first arm, the second arm, the robot wrist portion and the torch rotating portion are independently driven to rotate by different motors, respectively, so that the torch shape can be adjusted according to the shape of the object to be welded. Posture is controlled,
The tip position of the torch is controlled so as to coincide with the welding location, and welding can be performed automatically.

[0004]

However, in the above-described conventional torch rotating device, since the torch is mounted and fixed at a position away from the rotation axis of the torch rotating portion via the torch mounting arm, the robot wrist is The torch mounting arm interferes with the upper surface of the second arm when rotating integrally with the torch rotation unit with respect to the second arm, for example, and with the lower surface of the second arm when rotating downward. Therefore, the rotation range of the robot wrist is limited by the interference of the torch mounting arm with the second arm.

Further, a cable for supplying gas or the like to the torch is connected to the torch, and since this cable passes through the side of the second arm substantially in parallel with it, the torch rotating part is attached to the robot wrist. When the cable rotates, the intermediate part of the cable interferes with the second arm, and the rotation range of the torch rotating part (torch) is limited by the cable. In particular, when the tip of the torch faces upward, the portion of the torch to which the cable is connected faces downward, so the downward cable is connected upward to the torch again near the torch attachment. As a result, the cable is substantially U-shaped, and when the torch rotation unit rotates with respect to the robot wrist in this state, it becomes easier to interfere with both side surfaces of the second arm, and the torch rotation unit (torch).
The rotation range of is narrower.

On the other hand, if the cable is made long enough to be easily bent, the rotation range of the torch can be increased by utilizing the bending of the cable. However, in this case, the cable may become entangled with the second arm while the robot wrist and the torch rotating unit are repeatedly rotated.

As described above, in the conventional torch rotating device,
Since the torch mounting arm and cable limit the control range of the torch posture and torch tip position, the teaching work of the robot becomes complicated and difficult depending on the shape of the object to be welded and the installation posture of the robot, and there is room for improvement. was there.

The present invention has been made in view of the above points, and an object of the present invention is to improve the rotating structure of the torch itself with respect to the wrist portion in the above-mentioned robot, thereby making the robot wrist portion and the torch respectively. The rotation range of is not restricted by a cable or the like, and the degree of freedom of the torch posture and the torch tip position can be increased to simplify the teaching work of the robot.

[0009]

In order to achieve the above object, according to the present invention, a robot wrist is arranged laterally of a robot arm, and a torch is supported on the robot wrist so as to be rotatable about its central axis. I decided to do it.

Specifically, in the invention of claim 1, the robot wrist is rotatably supported at the arm tip end of the robot about an axis substantially perpendicular to the longitudinal direction of the arm, and the robot wrist. It is premised on a torch rotating device for an industrial robot, which is provided with a torch supported by the torch and extending in a direction substantially perpendicular to the axis of rotation of the torch to which a cable is connected.

The robot wrist is arranged on the side of the robot arm, the torch is supported on the robot wrist so as to be rotatable about the central axis of the torch, and the torch is driven by rotating the torch about the central axis. Provide means.

As a result, the robot wrist is pivotally supported on the side of the tip of the robot arm, and the torch is rotatably supported on the robot wrist about its central axis. The torch mounting arm that is placed away from the heart and rotates with respect to the robot wrist is no longer required, and the rotation range of the robot wrist is limited when rotating the robot wrist with respect to the robot arm. I will not receive it.

Further, the torch rotates about the axis of the torch with respect to the robot wrist portion by the driving means. However, no matter how the torch rotates, it only rotates about the central axis of the torch. The cable connected to is always located on one side of the robot arm, that is, on the wrist side of the robot, and never moves from one side of the robot arm to the other side. Therefore, the middle portion of the cable does not interfere with the side surface of the robot arm and the cable does not get entangled with the robot arm, and the rotation range of the torch can be expanded without limitation.

As a result of the above, the range in which the torch posture and the torch tip position can be set is wider than that of the conventional one,
The range of use of the robot is expanded, and the teaching work of the robot can be simplified.

Further, since the torch need only be supported on the wrist of the robot so as to be rotatable about its central axis, the shape of the torch is not limited, and it is not necessary to make a dedicated torch, and a normal torch can be used. You can

According to a second aspect of the present invention, in the first aspect of the present invention, the robot wrist portion is provided with a torch through hole for rotatably supporting the torch about the central axis of the torch. According to the present invention, since the torch can be rotatably supported inside the wrist of the robot, the torch support structure is simplified. Moreover, since it is not necessary to separately provide a mounting member or the like that projects from the robot wrist for supporting the torch, the entire robot wrist can be made compact.

According to a third aspect of the present invention, in the first or second aspect of the invention, the torch drive means is provided on the wrist of the robot. As a result, a motor and a transmission mechanism for rotating the torch can be arranged in the vicinity of the location supporting the torch, so that the transmission mechanism can be installed without hindering the rotation of the robot wrist or robot arm. It can be easily constructed and the transmission efficiency can be improved.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an arm tip portion of a multi-joint welding robot having a six-axis degree of freedom equipped with a torch rotation device according to an embodiment of the present invention (note that a portion not shown has the same configuration as a known robot). , Detailed description is omitted). Reference numeral 1 denotes a cylindrical robot arm for the third axis, which is rotatable about its axis a by a motor (not shown). A transmission shaft 6 extending concentrically with the arm 1 is inserted into the arm 1, and the transmission shaft 6 serves as the robot arm 1.
Is rotatably supported by a support body 3 that closes the tip end of the robot arm 1 through bearings 4 and 4, and is rotated by a motor (not shown) different from the motor that rotates the robot arm 1. A transmission mechanism housing 2 is attached and fixed to the support 3 at the tip of the robot arm 1 so as to rotate integrally with the arm 1.

The tip end of the transmission shaft 6 is the transmission mechanism housing 2
The driving bevel gear 7 is fixed to the distal end of the driving bevel gear 7 so as to rotate integrally therewith. This drive bevel gear 7 is used for the transmission mechanism housing 2
It meshes with the driven bevel gear 8 arranged inside. The driven bevel gear 8 is rotationally integrally attached and fixed to one end of a transmission shaft 10 having a rotation shaft center a of the transmission shaft 6 and a rotation shaft center b in the vertical direction. The transmission shaft 10 is rotatably supported in the transmission mechanism housing 2 by bearings 11 and 11 in a state where it is rotatably secured inside the transmission mechanism housing 2, and the other end of the transmission shaft 10 is located laterally of the transmission mechanism housing 2. The robot wrist portion 15 arranged at the lower side (in the figure) is integrally fixed by rotation through the speed reducer 9,
The robot wrist 15 is rotatably supported in the transmission mechanism housing 2 via a bearing 12, and is rotated about the axis b of the transmission shaft 10 by the rotation of the transmission shaft 6.

A through hole 16 is formed in the robot wrist portion 15 near the transmission mechanism housing 2 and extends in a direction of an axis c substantially perpendicular to the axis b of the transmission shaft 10.
An output gear 18 is rotatably supported in the 6 by bearings 13 and 13 so as to be rotatable around an axis c. This output gear 1
8, an output flange 23 is rotationally and integrally attached and fixed to the left side surface of the robot wrist portion 15. The output gear 18 or the output flange 23 is provided with a torch through hole 17 centered on the axis c.

The transmission mechanism housing 2 inside the robot wrist 15.
A drive gear 22 that meshes with the output gear 18 is provided on the front side (the left side in the drawing) of the portion opposite to the above (the lower side in the drawing). The drive gear 2 is provided on the rear side of the robot wrist 15.
An output shaft 19 extending concentrically with 2 is rotatably supported by bearings 14, 14, and a drive gear 22 is fixed to one end of the output shaft 19 so as to rotate together. On the other hand, a motor 20 as driving means is drivingly connected to the other end of the output shaft 19 via a speed reduction mechanism 21, and the speed reduction mechanism 21 and the motor 20 are attached and fixed to the robot wrist 15.

In the torch through hole 17 of the output gear 18 in the through hole 16 of the robot wrist 15, a torch 30 having a nozzle 33 at its tip is provided with a cylindrical supporting portion 31.
It is supported through. Support part 31 of this torch 30
Includes torch fixing tools 25, 2 which are fixedly attached to the output flange 23 from the side opposite to the output gear 18 so as to rotate integrally.
6 is integrally provided, and the torch 30 is rotationally and drivably coupled to the output gear 18 by fixing the torch fixture 25 and the output flange 23. Then, the motor 20 provided on the robot wrist 15
The torch 30 is rotated around its central axis by the operation of the (driving means).

A connecting portion 32 is provided on the base end side of the supporting portion 31 of the torch 30, and a cable 35 for supplying welding gas or the like to the torch 30 is connected to the connecting portion 32. The cable 35 extends along the robot arm 1 toward the base end thereof and is connected to a welding gas supply unit fixed to a predetermined portion of the welding robot. Also,
The tip portion of the torch 30 is bent so as to face a direction forming a predetermined angle with the central axis thereof.

The operation of the robot torch rotation device configured as described above will be described. When the robot arm 1 is rotated around the axis a by a motor (not shown), the robot wrist 15 connected and supported to the arm 1 via the support 3 and the transmission mechanism housing 2 is rotated around the axis a together with the torch 30. To rotate integrally.

When the transmission shaft 6 in the arm 1 is rotated by a motor (not shown), this rotation is transmitted to the robot wrist 15 via the drive and driven bevel gears 7, 8, the transmission shaft 10, and the speed reducer 9. As a result, the robot wrist 15 rotates about the axis b independently of the rotation around the axis a due to the rotation of the robot arm 1. At this time, torch 30
Rotates integrally with the robot wrist 15 around the axis b.

Further, the torch 30 is the robot arm 1
Independently of the rotation around the axis a due to the rotation of the robot wrist 15 and the rotation around the axis b due to the rotation of the robot wrist portion 15, the rotation of the torch center axis is performed by the drive of the motor 20 through the reduction mechanism 21, the drive gear 22, and the output gear 18. By rotating, the nozzle 33 at the tip of the torch 30 can be moved in an arc around the center axis of the torch.

Then, the rotation of all the motors of the robot including the above three motors is controlled to drive the joints of the robot arm 1 and the like, and the attitude of the torch 30 is adjusted so as to match the shape of the object to be welded. Further, the position of the nozzle 33 is controlled so that the nozzle 33 of the torch 30 coincides with the welding location.

Therefore, in this embodiment, the robot wrist 15 is arranged laterally of the robot arm 1 and the torch 30 is supported on the robot wrist 15 so as to be rotatable about its central axis. It is not necessary to provide a conventional torch mounting arm or the like that is arranged at a position distant from the rotation axis center and rotates with respect to the robot wrist section. Therefore, the robot wrist section 15 has an axis b with respect to the robot arm 1. It can rotate around the entire circumference.

Further, since the torch 30 is rotatably supported on the robot wrist 15 about its central axis, when the torch 30 is rotated with respect to the robot wrist 15 by the motor 20, the rotation of the torch 30 is caused by the rotation of the torch 30. Cable 3 connected to the torch 30 only around the central axis of
5 is always the robot wrist 15 with respect to the robot arm 1
It is located on the side of and does not move to the side opposite to the robot wrist 15. Therefore, as the torch 30 rotates about its central axis, the middle part of the cable 35 does not interfere with the side surface of the robot arm 1 or entangle with the robot arm 1, and the torch 30 rotates with respect to the robot wrist 15. The possible range can be expanded to the full circumference range.

From the above, the controllable range of the attitude of the torch 30 and the position of the nozzle 33 at the tip of the torch is expanded as compared with the conventional one, so that the welding robot can be applied without being influenced by the shape of the welding object. It is possible to expand the usable range of the robot and facilitate the teaching work of the robot.

Further, since the torch 30 need only be supported on the robot wrist 15 so as to be rotatable about its central axis,
It is not necessary to create a special torch, and it is possible to use a conventional torch having a simple structure conventionally used.

A through hole 16 is formed in the robot wrist 15.
Is provided, the output gear 18 is supported therein, and the torch 30 is penetratingly supported in the torch through hole 17 of the output gear 18. Therefore, the torch 30 can be rotatably supported by the robot wrist 15 itself. Therefore, the supporting structure of the torch 30 can be simplified. Further, since it is not necessary to separately provide a projecting member or the like for supporting the torch 30 on the robot wrist portion 15, it is possible to improve the space efficiency of the entire robot wrist portion 15 and reduce the size thereof.

Further, since the motor 20 for driving the torch 30 is provided in the robot wrist portion 15, the drive system for driving the torch 30 can have a simple structure and its driving efficiency can be improved. be able to.

In the above embodiment, the welding robot having 6-axis degrees of freedom is used. However, it is a multi-joint type robot having multi-axis degrees of freedom in which the robot arm does not rotate around its axis. The present invention can also be applied.

The present invention can be applied not only to the robot having the welding torch as in the above embodiment, but also to a torch rotating device for a cutting or heating robot having the same torch.

[0036]

As described above, according to the invention of claim 1, the robot wrist of the articulated robot is arranged on the side of the robot arm, and the torch is rotated around the center axis of the robot wrist. By supporting the torch and rotating the torch around the central axis by the driving means, the degree of freedom of the torch posture and the torch tip position can be increased, the usable range can be expanded, and the robot can be used. The teaching work can be simplified.

According to the invention of claim 2, since the torch through hole for penetrating and supporting the torch is provided in the robot wrist, the torch support structure can be simplified and the robot wrist can be downsized. Can be planned.

According to the third aspect of the present invention, since the driving means for driving the torch is provided on the robot wrist, the structure of the driving means can be simplified without hindering the rotation of the robot wrist or the robot arm. The driving efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a torch rotating device of a robot according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 robot arm 2 transmission mechanism storage part 3 support body 4,11-14 bearing 6,10 transmission shaft 7 drive bevel gear 8 driven bevel gear 9 reducer 15 robot wrist 16 through hole 17 torch through hole 18 output gear 19 output shaft 20 Motor 21 Reduction Mechanism 22 Drive Gear 23 Output Flange 25, 26 Torch Fixing Tool 30 Torch 31 Supporting Part 32 Connection Part 33 Nozzle 35 Cable

Claims (3)

[Claims] 1. A robot wrist which is rotatably supported on the arm tip of the robot about an axis substantially perpendicular to the longitudinal direction of the arm, and a robot wrist supported by the robot wrist and substantially the same as the axis of rotation thereof. In an industrial robot torch rotating device including a torch to which a cable is connected and extending in a vertical direction, the robot wrist is disposed on a side of a robot arm, and the torch has a central axis of the torch on the robot wrist. A torch rotation device for an industrial robot, which is rotatably supported around and includes a torch drive means for rotating the torch around its central axis. 2. The torch rotating device for an industrial robot according to claim 1, wherein the robot wrist has a torch through hole for supporting the torch rotatably around the central axis of the torch. A torch rotation device for industrial robots characterized by. 3. A torch rotating device for an industrial robot according to claim 1, wherein the torch driving means is provided on the wrist of the robot.